The cellular telephone industry has had an enormous development in the world in the past decades. From the initial analog systems, such as those defined by the standards AMPS (Advanced Mobile Phone System) and NMT (Nordic Mobile Telephone), the development has during recent years been almost exclusively focused on standards for digital solutions for cellular radio network systems, such as D-AMPS (e.g., as specified in EIA/TIA-IS-54-B and IS-136) and GSM (Global System for Mobile Communications). Currently, the cellular technology is entering the so called 3rd generation 3G, providing several advantages over the former, 2nd generation, digital systems referred to above.
Many of the advances made in mobile phone technology are related to functional features, such as better displays, more efficient and longer lasting batteries, and means for generating polyphonic ring signals. One functional feature which has been more and more common is built-in cameras. Cameras with video camera functionality are today available in several mobile phones. With the entrance of high bit-rate services, such as EDGE (Enhanced Data-rates for GSM) and 3G the usability for video-related services will increase. For one thing, mobile video telephony, with simultaneous communication of sound and moving images, has recently become commercially available.
For stationary use, video conference systems generally include a camera mounted on or beside a communication terminal, such as a personal computer PC, or integrated in an IP phone. Use of such a system is fairly straightforward, as the user is positioned in front of the terminal with the camera aiming towards the user. However, mobile video conferencing with face to face transmission suffers from one main drawback. When communicating through a mobile handheld terminal, the user has to hold the terminal steady in front of the face so that the receiving party can see the face of the user, i.e. the sending party. The terminal has to be aimed more or less 90° to the face, in order to get a usable image of the user. A problem is that the user will get tired in the arm, and thereby tend to tremble and also hold the terminal lower and lower. The result is that the image captured will show more of the neck and chin portion of the user, than the upper part of the face. This lowers the value of the service as it is experienced as difficult to use. Furthermore, it is appreciated that consumers may want to be able to view the surroundings when engaged in a video conference, but a mobile phone will block at least parts of the field of view if it has to be held in front of the face.